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Xiangqi Meng,
Jiangxue Wu,
Changchuan Pan,
Hui Wang,
Xiaofang Ying,
Yi Zhou,
Hongyan Yu,
Yufang Zuo,
Zhizhong Pan,
Ran-Yi Liu, Wenlin Huang
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ABSTRACT: BACKGROUND & AIMS: Altered functions of microRNAs (miRNAs) have been associated with colorectal cancer (CRC). MiR-212 is transcribed from a stable intron of a non-protein coding gene, and is reportedly downregulated in different tumor types. We investigated the role of miR-212 in colorectal carcinogenesis and progression. METHODS: We analyzed the expression of miR-212 by real-time PCR analysis of colorectal cell lines and 180 paired tumor samples and surrounding healthy tissue. We overexpressed and knocked down miR-212 in CRC cell lines and assessed the in vitro effects. We also studied the effects of miR-212 overexpression on metastasis of tumors grown from HCT116 cells in nude mice. RESULTS: Overexpression of miR-212 inhibited CRC cell migration and invasion in vitro and formation of intrahepatic and pulmonary metastasis in vivo. We identified manganese superoxide dismutase (MnSOD) mRNA as a direct target of miR-212, and observed an inverse correlation between the level of miR-212 and MnSOD protein in colorectal tumor samples. MnSOD was required for downregulation of epithelial markers and upregulation of mesenchymal markers in CRC cells, indicating that it promoted the epithelial-mesenchymal transition (EMT). Overexpression of miR-212 reduced the levels of MnSOD to block the EMT process. Loss of heterozygosity and promoter hypermethylation each contributed to the downregulation of miR-212. Reduced levels of miR-212 were associated with a more aggressive tumor phenotype and short disease-free survival times of patients (P =.0045; overall survival, P =.0015). CONCLUSIONS: MiR-212 is downregulated in human CRC tissues via genetic and epigenetic mechanisms. MiR-212 might prevent tumor progression by targeting MnSOD mRNA; reduction of miR-212 could be a prognostic marker for patients with CRC. MiR-212 and MnSOD might also be therapeutic targets for cancer.
Gastroenterology 04/2013; · 11.68 Impact Factor
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ABSTRACT: Identification of high-risk prognostic markers for stage II colorectal cancer (CRC) is currently a big challenge. CD133 is one of the most commonly used CRC stem cell markers. However, its specificity is controversial. Recent studies have demonstrated that the AC133 epitope of CD133, not the CD133 protein, is responsible for cancer stem cell identification. The aim of this study was to investigate the clinical significance of AC133 expression in stage II CRC. Two antibodies against CD133, including AC133 and Ab19898, were compared for their expression characteristics. AC133 was chosen for further immunohistochemical assessment on 176 stage II CRC primary tumors with at least 12 examined lymph nodes. The cutoff value for positive rate of AC133 expression was determined by ROC curve analysis. AC133 was analyzed for correlations with clinicopathological and prognostic parameters. The results indicated that AC133 was negative in adjacent noncancerous colorectal mucosa while positive in 116 cases (65.9 %) of primary tumors. AC133 expression was significantly correlated with preoperative serum carcinoembryonic antigen level (p = 0.006) and tumor differentiation grade (p = 0.019). Furthermore, high AC133 expression was identified as a significant predictor for poor disease-free survival and overall survival at both univariate (p = 0.009, 0.013, respectively) and multivariate levels (p = 0.022, 0.026, respectively). Our data suggest that AC133 is an independent adverse prognostic factor and a potential marker for survival classification in stage II CRC patients.
Medical Oncology 03/2013; 30(1):356. · 2.14 Impact Factor
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ABSTRACT: Compound 1 (VEC-5) was identified as a potent small molecular HIV-1 VIF inhibitor that targets the VIF-ElonginC interaction. A structure-activity relationship study was carried out to develop compounds with improved efficacy against HIV-1 and 49 indolizine derivatives of three categories were designed and synthesized. We found that 5 compounds exhibited promising anti-HIV-1 activity and the most active compound 2g had an IC(50) value of 11.0 μM. These results provide new information to develop highly potent small-molecule HIV-1 VIF inhibitors. © 2013 John Wiley & Sons A/S.
Chemical Biology & Drug Design 02/2013; · 2.28 Impact Factor
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Fa-Jun Xie,
Peng Zhao,
Yi-Ping Zhang,
Fei-Ye Liu,
Xi-Lin Nie,
Ying-Hui Zhu,
Xin-Min Yu,
Qiu-Qing Zheng,
Wei-Min Mao,
Hong-Yang Lu,
Hong Wei, Wenlin Huang
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ABSTRACT: Pancreatic cancer is one of the most lethal human malignancies with a very low 5-year survival rate, which highlights urgent needs for more effective therapeutic strategies. In this study, we examined the potential therapeutic effects of an adenovirus encoding human interferon gamma (Ad-IFNγ) on pancreatic carcinoma cells Capan-2 in vitro and in vivo. The results indicated that Ad-IFNγ could significantly inhibit tumor cell growth via inducing cell apoptosis. After infection, IFNγ expressed durably and stably in xenografts, predominantly in tumor tissue, while much less in blood and liver. Thus, adenovirus-mediated intratumoral injection of human IFNγ gene could be an effective gene therapeutic system for the treatment of pancreatic carcinoma. Anat Rec, 00:000-000, 2013. © 2013 Wiley Periodicals, Inc.
The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology 02/2013; · 1.47 Impact Factor
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ABSTRACT: The HIV-1 viral infectivity factor (VIF) protein is essential for viral replication. VIF recruits cellular ElonginB/C-Cullin5 E3 ubiquitin ligase to target the host antiviral protein APOBEC3G (A3G) for proteasomal degradation. Thus, the A3G-Vif-E3 complex represents an attractive target for the development of novel anti-HIV drugs. In this study, we describe the design and synthesis of indolizine derivatives as VIF inhibitors targeting the VIF-ElonginC interaction. Many of the synthesized compounds exhibited obvious inhibition activities of VIF-mediated A3G degradation, and 5 compounds showed improvement of activity compared to the known VIF inhibitor VEC-5 (1) with IC[Formula: see text] values about 20 [Formula: see text]M. The findings described here will be useful for the development of more potent VIF inhibitors.
Molecular Diversity 02/2013; · 3.15 Impact Factor
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ABSTRACT: Endocrine disrupting chemicals (EDCs) that are frequently detected in bodies of water downstream from sewage treatment facilities can have adverse impacts on fish and other aquatic organisms. To properly assess risk(s) from EDCs, tools are needed that can establish linkages from chemical exposures to adverse outcomes. Traditional methods of testing chemical exposure and toxicity using experimental animals are excessively resource- and time-consuming. In line with EPA's goal of reducing animal use in testing, these traditional screening methods may not be sustainable in the long term, given the ever increasing number of chemicals that must be tested for safety. One of the most promising ways to reduce costs and increase throughput is to use cell cultures instead of experimental animals. In accordance with National Research Council's vision on 21st century toxicity testing, we have developed a cell culture-based metabolomics approach for this application. Using a zebrafish (Danio rerio) liver cell line (ZFL), we have applied NMR-based metabolomics to investigate responses of ZFL cells exposed to 17α-ethynylestradiol (EE2). This analysis showed that metabolite changes induced by EE2 exposure agree well with known impacts of estrogens on live fish. The results of this study demonstrate the potential of cell-based metabolomics to assess chemical exposure and toxicity for regulatory application.
Aquatic toxicology (Amsterdam, Netherlands) 01/2013; 130-131C:184-191. · 3.12 Impact Factor
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ABSTRACT: RNA interference (RNAi) has risen as a gold standard for validating gene function in basic life science studies, and provides a promising therapeutic modality for the treatment of cancer and other diseases. This mini-review focuses on the potential of small interfering RNA (siRNA) in anti-cancer treatment, including the establishment and screen of cancer-associated siRNA library and their applications in anticancer drug target discovery and cancer therapy. The article also describes the current delivery approaches of siRNAs using lipids, polymers, especially gold nanoparticles to realize significant gene silencing and tumor growth regression.
Chinese journal of cancer 01/2013;
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ABSTRACT: Influenza A virus is an important pathogenic virus known to induce host cell cycle arrest in G0/G1 phase and create beneficial conditions for viral replication. However, how the virus achieves arrest remains unclear. We investigated the mechanisms underlying this process and found that the non-structural protein 1 (NS1) is required. Based on this finding, we generated a viable influenza A virus (H1N1) lacking the entire NS1 gene to study the function of this protein in cell cycle regulation. Besides some cell cycle regulators were changed, the concentration and activity of RhoA protein, which is thought to be pivotal for G1/S phase transition, was also decreased with over-expressing NS1. At the same time, cell cycle regulator pRb, the downstream of RhoA kinase's phosphorylation level was decreased in an NS1-dependent manner. These findings indicate that the NS1 protein induces G0/G1 cell cycle arrest mainly through interfering with the RhoA/pRb signalling cascade, thus providing favorable conditions for viral protein accumulation and replication. We further investigated the NS1 protein of avian influenza virus (H5N1) and found it also can decrease the expression and activity of RhoA, suggesting that the H5N1 virus may affect the cell cycle through the same mechanism. The NS1/RhoA/pRb cascade which can induce the G0/G1 cell cycle arrest identified here provides a unified explanation for the seemingly different NS1 functions involved in viral replication events. Our findings shed light on the mechanism of influenza virus replication and open new avenues for understanding the interaction between pathogens and hosts.
Journal of Virology 01/2013; · 5.40 Impact Factor
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ABSTRACT: Clock genes drive about 5-15% of genome-wide mRNA expression, and disruption of the circadian clock may deregulate the cell's normal biological functions. Cryptochrome 1 is a key regulator of the circadian feedback loop and plays an important role in organisms. The present study was conducted to investigate the expression of Cry1 and its prognostic significance in colorectal cancer (CRC). In addition, the function of Cry1 in human CRC was investigated in cell culture models.
Real-time quantitative PCR, Western blot analysis and immunohistochemistry were used to explore Cry1 expression in CRC cell lines and primary CRC clinical specimens. MTT and colony formation assays were used to determine effects on cellular proliferation ability. The animal model was used to explore the Cry1 impact on the tumor cellular proliferation ability in vivo. Transwell assays were performed to detect the migration ability of the cell lines. Statistical analyzes were applied to evaluate the diagnostic value and the associations of Cry1 expression with clinical parameters.
Cry1 expression was up regulated in the majority of the CRC cell lines and 168 primary CRC clinical specimens at the protein level. Clinical pathological analysis showed that Cry1 expression was significantly correlated with lymph node metastasis (p = 0.004) and the TNM stage (p = 0.003). High Cry1 expression was associated with poor overall survival in CRC patients (p = 0.010). Experimentally, we found that up-regulation of Cry1 promoted the proliferation and migration of HCT116 cells, while down-regulation of Cry1 inhibited the colony formation and migration of SW480 cells.
These results suggest that Cry1 likely plays important roles in CRC development and progression andCry1 may be a prognostic biomarker and a promising therapeutic target for CRC.
PLoS ONE 01/2013; 8(4):e61679. · 4.09 Impact Factor
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Ran-Yi Liu,
Ying-Hui Zhu,
Ling Zhou,
Peng Zhao,
Hong-Li Li,
Lan-Cai Zhu,
Hong-Yu Han,
Huan-Xin Lin,
Liang Kang,
Jiang-Xue Wu, Wenlin Huang
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ABSTRACT: BACKGROUND: Interferon-gamma (IFN-gamma) is regarded as a potent antitumor agent, but its clinical application is limited by its short half-life and significant side effects. In this paper, we tried to develop IFN-gamma gene therapy by a replication defective adenovirus encoding the human IFN-gamma (Ad-IFNgamma), and evaluate the antitumoral effects of Ad-IFNgamma on nasopharyngeal carcinoma (NPC) cell lines in vitro and in xenografts model. METHODS: The mRNA levels of human IFN-gamma in Ad-IFNgamma-infected NPC cells were detected by reverse transcription-polymerase chain reaction (RT-PCR), and IFN-gamma protein concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in the culture supernatants of NPC cells and tumor tissues and bloods of nude mice treated with Ad-IFNgamma. The effects of Ad-IFNgamma on NPC cell proliferation was determined using MTT assay, cell cycle distribution was determined by flow cytometry analysis for DNA content, and cells apoptosis were analyzed by Annexin V-FITC/7-AAD binding assay and hoechst 33342/PI double staining. The anti-tumor effects and toxicity of Ad-IFNgamma were evaluated in BALB/c nude mice carrying NPC xenografts. RESULTS: The results demonstrated that Ad-IFNgamma efficiently expressed human IFN-gamma protein in NPC cell lines in vitro and in vivo. Ad-IFNgamma infection resulted in antiproliferative effects on NPC cells by inducing G1 phase arrest and cell apoptosis. Intratumoral administration of Ad-IFNgamma significantly inhibited the growth of CNE-2 and C666-1 cell xenografts in nude mice, while no significant toxicity was observed. CONCLUSIONS: These findings indicate IFN-gamma gene therapy mediated by replication defective adenoviral vector is likely a promising approach in the treatment of nasopharyngeal carcinoma.
Journal of Translational Medicine 12/2012; 10(1):256. · 3.41 Impact Factor
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Jingshu Wang,
Wei Guo,
Wangbing Chen,
Wendan Yu,
Yun Tian,
Lingyi Fu,
Dingbo Shi,
Bing Tong,
Xiangsheng Xiao, Wenlin Huang,
Wuguo Deng
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ABSTRACT: Ursolic acid (UA), a natural pentacyclic triterpenoid carboxylic acid, is largely distributed in medical herbs and edible plants. Melatonin is an indoleamine compound produced in the pineal gland and also a plant-derived product. Both UA and melatonin have been shown to inhibit cancer cell growth in numerous studies, but they have never been combined altogether as an anticolon cancer treatment. In this study, we investigated whether the association between UA and melatonin leads to an enhanced antiproliferative and pro-apoptotic activities in colon cancer SW480 and LoVo cells. We found that combined treatment with UA and melatonin significantly enhanced inhibition of cell viability and migration, promoted changes in cell morphology and spreading, and increased induction of apoptosis, thereby potentiating the effects of UA alone in colon cancer cells. Moreover, we found that the enhanced effects of UA and melatonin combination are mediated through simultaneous modulation of cytochrome c/caspase, MMP9/COX-2, and p300/NF-κB signaling pathways. Combined treatment with UA and melatonin triggered the release of cytochrome c from the mitochondrial intermembrane space into the cytosol, induced cleavage of caspase and PARP proteins, enhanced inhibition of MMP9 and COX-2 expression, promoted p300 and NF-κB translocation from cell nuclei to cytoplasm, and abrogated NF-κB binding and p300 recruitment to COX-2 promoter in colon cancer cells. These results, therefore, demonstrated that melatonin potentiated the antiproliferative and pro-apoptotic effects of UA in colon cancer cells by modulating multiple signaling pathways and suggest that such a combinational treatment might potentially become an effective way in colon cancer therapy.
Journal of Pineal Research 12/2012; · 5.79 Impact Factor
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Mathilde Guerin,
Chaonan Qian,
Qian Zhong,
Qian Cui,
Yunmiao Guo,
Jinxin Bei,
Jianyong Shao,
Xiaofeng Zhu, Wenlin Huang,
Jiangxue Wu,
Ranyi Liu,
Qiang Liu,
Jing Wang,
Weihua Jia,
Xiaohui Zheng,
Yixin Zeng
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ABSTRACT: Sun Yat-sen University Cancer Center (SYSUCC) is currently conducting many translational studies to improve cancer patients' condition through early diagnosis, discovering new treatments, improving treatment outcomes, and better classification and prognosis of cancer. SYSUCC is a leading institution for treating nasopharyngeal carcinoma (NPC) and carrying out research into the disease. The center has performed several large-scale studies that have produced new insights, such as a genome-wide analysis study, which has allowed researchers to identify new genetic risk factors for NPC; the findings are significant toward building a risk prediction model for NPC. Other researchers are using molecular biological methods to identify new biomarkers, which will allow a better classification and prognosis of this disease. Drug discovery, especially for molecular targeted therapy, is also an active field of research at SYSUCC, not only for NPC treatment, but also for, among others, cancers of the head, neck, and liver. As an alternative to Western medicine, scientists also use derivatives of natural products from Traditional Chinese Medicine to develop new compounds. The tumor biobank at SYSUCC, one of the largest in China, play an essential role in producing clinical applications from research findings. Translational oncology is a promising field, and scientists and clinicians from SYSUCC will continue to work in synergy to develop new anticancer therapies.
Science China. Life sciences 11/2012; · 2.02 Impact Factor
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ABSTRACT: The IKK/NF-κB pathway is an essential signalling process initiated by the cell as a defence against viral infection like influenza virus. This pathway is therefore a prime target for viruses attempting to counteract the host response to infection. Here, we report that the influenza A virus NS1 protein specifically inhibits IKK-mediated NF-κB activation and production of the NF-κB induced antiviral genes by physically interacting with IKK through the C-terminal effector domain. The interaction between NS1 and IKKα/IKKβ affects their phosphorylation function in both the cytoplasm and nucleus. In the cytoplasm, NS1 not only blocks IKKβ-mediated phosphorylation and degradation of IκBα in the classical pathway but also suppresses IKKα-mediated processing of p100 to p52 in the alternative pathway, which leads to the inhibition of nuclear translocation of NF-κB and the subsequent expression of downstream NF-κB target genes. In the nucleus, NS1 impairs IKK-mediated phosphorylation of histone H3 Ser 10 that is critical to induce rapid expression of NF-κB target genes. These results reveal a new mechanism by which influenza A virus NS1 protein counteracts host NF-κB-mediated antiviral response through the disruption of IKK function. In this way, NS1 diminishes antiviral responses to infection and, in turn, enhances viral pathogenesis.
Cellular Microbiology 08/2012; · 5.46 Impact Factor
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ABSTRACT: A crucial step in metabolomic analysis of cellular extracts is the cell quenching process. The conventional method first uses
trypsin to detach cells from their growth surface. This inevitably changes the profile of cellular metabolites since the detachment
of cells from the extracellular matrix alters their physiology. This conventional method also includes time consuming wash/centrifuge
steps after trypsinization, but prior to quenching cell activity. During this time, a considerable portion of intracellular
metabolites are lost, rendering the conventional method less than ideal for application to metabolomics. We report here a
novel sample preparation method for metabolomics applications using adherent mammalian cells, which eliminates the time consumption
and physiological stress of the trypsinization and wash/centrifuge steps. This new method was evaluated in the study of metabolic
changes caused by 17α-ethynylestradiol (EE2) in estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 human breast
cancer cell lines using NMR spectroscopy. The results demonstrated that our direct cell quenching method is rapid, effective,
and exhibits greater metabolite retention, providing an increase of approximately a factor of 50 compared to the conventional
method.
Metabolomics 04/2012; 5(2):199-208. · 4.51 Impact Factor
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ABSTRACT: There is a pressing need to increase the throughput of NMR analysis in fields such as metabolomics and drug discovery. Direct injection (DI) NMR automation is recognized to have the potential to meet this need due to its suitability for integration with the 96-well plate format. However, DI NMR has not been widely used as a result of some insurmountable technical problems; namely: carryover contamination, sample diffusion (causing reduction of spectral sensitivity), and line broadening caused by entrapped air bubbles. Several variants of DI NMR, such as flow injection analysis (FIA) and microflow NMR, have been proposed to address one or more of these issues, but not all of them. The push-through direct injection technique reported here overcomes all of these problems. The method recovers samples after NMR analysis, uses a "brush-wash" routine to eliminate carryover, includes a procedure to push wash solvent out of the flow cell via the outlet to prevent sample diffusion, and employs an injection valve to avoid air bubbles. Herein, we demonstrate the robustness, efficiency, and lack of carryover characteristics of this new method, which is ideally suited for relatively high throughput analysis of the complex biological tissue extracts used in metabolomics, as well as many other sample types. While simple in concept and setup, this new method provides a substantial improvement over current approaches.
The Analyst 03/2012; 137(9):2226-32. · 4.23 Impact Factor
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Tao Zuo,
Donglai Liu,
Wei Lv,
Xiaodan Wang,
Jiawen Wang,
Mingyu Lv, Wenlin Huang,
Jiaxin Wu,
Haihong Zhang,
Hongwei Jin,
Liangren Zhang,
Wei Kong,
Xianghui Yu
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ABSTRACT: The HIV-1 viral infectivity factor (Vif) protein is essential for viral replication. Vif recruits cellular ElonginB/C-Cullin5 E3 ubiquitin ligase to target the host antiviral protein APOBEC3G (A3G) for proteasomal degradation. In the absence of Vif, A3G is packaged into budding HIV-1 virions and introduces multiple mutations in the newly synthesized minus-strand viral DNA to restrict virus replication. Thus, the A3G-Vif-E3 complex represents an attractive target for development of novel anti-HIV drugs. In this study, we identified a potent small molecular compound (VEC-5) by virtual screening and validated its anti-Vif activity through biochemical analysis. We show that VEC-5 inhibits virus replication only in A3G-positive cells. Treatment with VEC-5 increased cellular A3G levels when Vif was coexpressed and enhanced A3G incorporation into HIV-1 virions to reduce viral infectivity. Coimmunoprecipitation and computational analysis further attributed the anti-Vif activity of VEC-5 to the inhibition of Vif from direct binding to the ElonginC protein. These findings support the notion that suppressing Vif function can liberate A3G to carry out its antiviral activity and demonstrate that regulation of the Vif-ElonginC interaction is a novel target for small-molecule inhibitors of HIV-1.
Journal of Virology 02/2012; 86(10):5497-507. · 5.40 Impact Factor
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ABSTRACT: Melatonin is an indoleamine secreted by the pineal gland as well as a plant-derived product that exerts potential anti-inflammatory properties, but the mechanisms of action remain unclear. Here, we investigated the roles of melatonin in regulation of proinflammatory mediators and identified the underlying mechanisms in human vascular smooth muscle (VSM) cell line CRL1999 stimulated by lipopolysaccharide (LPS). We found that treatment with melatonin significantly inhibited the production and expression of TNF-α and interleukin (IL)-1β, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase, prostaglandin E(2) (PGE2), and nitric oxide (NO) in a dose-dependent manner. Moreover, we also found that the suppression of proinflammatory mediators by melatonin was mediated through inhibition of MAPK, NF-κB, c/EBPβ, and p300 signaling in LPS-stimulated CRL1999 cells. Treatment with melatonin markedly inhibited phosphorylation of ERK1/2, JNK, p38 MAPK, IκB-α, and c/EBPβ, blocked binding of NF-κB and c/EBPβ to promoters, and suppressed p300 histone acetyltransferase (HAT) activity and p300 HAT-mediated NF-κB acetylation. Transfection with an ERK-, IκB-, or c/EBPβ-specific siRNA or pretreatment with an ERK-, p38 MAPK-, or p300-selective inhibitor considerably abrogated the melatonin-mediated inhibition of proinflammatory mediators. Conversely, exogenous overexpression of a constitutively active p300, but not its HAT mutant, effectively reversed the melatonin-mediated inhibitions. Collectively, these results indicate that melatonin suppresses proinflammatory mediators by simultaneously targeting the multiple signaling such as ERK/p38 MAPK, c/EBPβ, NF-κB, and p300, in LPS-stimulated VSM cell line CRL1999, and suggest that melatonin is a potential candidate compound for the treatment of proinflammatory disorders.
Journal of Pineal Research 01/2012; 53(2):154-65. · 5.79 Impact Factor
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ABSTRACT: A recombinant adenovirus encoding human endostatin gene, E10A, has finished phase II trials for head and neck cancer. However, the rigid storage temperature (-80°C) and the toxicity of glycerol in the E10A liquid preparation limited its clinical application. In this study, lyophilization was applied to develop a stable E10A lyophilized powder without glycerol that is able to maintain biological activity at 4°C and suitable for intravenous administration. The E10A lyophilized formulations composed of nontoxic and already clinically used excipients were characterized in terms of the pH change during freezing, the eutectic melting temperature (T(eu)) and the collapse temperature (T(c)). Freeze thawing tests were carried out to examine the protective effect of various excipients during freezing. Mannitol and its combinations with sucrose or inulin showed effective protection of E10A. The E10A lyophilized powders were analyzed by particle size measurement, residual humidity quantification, infectivity assay and gene expression level. An optimized formulation (formulation I1) yielded a good recovery of 76% of the starting infectivity after lyophilization and 89% of the original infectivity after storage at 4°C for 180 days. Also the gene expression capability of E10A in formulation I1 was maintained after lyophilization. In addition, it was found that the matrix of amorphous excipients, mannitol combinations with sucrose or inulin, was indispensible in protecting E10A against the stress of freezing and dehydration. Hereby, the E10A lyophilized powder with eliminated glycerol toxicity and improved stability could enhance the applicability of E10A for cancer gene therapy through intravenous administration.
International journal of pharmaceutics 01/2012; 427(2):145-52. · 2.96 Impact Factor
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Jingshu Wang,
Xiangsheng Xiao,
Yun Zhang,
Dingbo Shi,
Wangbing Chen,
Lingyi Fu,
Liqun Liu,
Fangyun Xie,
Tiebang Kang, Wenlin Huang,
Wuguo Deng
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ABSTRACT: Melatonin exhibits anti-inflammatory and anticancer effects and could be a chemopreventive and chemotherapeutic agent against cancers, but the precise mechanisms involved remain largely unresolved. In this study, we evaluated the mechanism of action of melatonin in human MDA-MB-361 breast cancer cells. Melatonin at pharmacological concentrations (10(-3) m) significantly suppressed cell proliferation and induced apoptosis in a dose-dependent manner. The observed suppression of proliferation was accompanied by the melatonin-mediated inhibition of COX-2, p300, and NF-κB signaling. Melatonin significantly inhibited COX-2 expression and prostaglandin E(2) (PGE2) production, abrogated p300 histone acetyltransferase activity and p300-mediated NF-κB acetylation, thereby blocking NF-κB binding and p300 recruitment to COX-2 promoter. Pretreatment with a COX-2- or p300-selective inhibitor abrogated the melatonin-induced inhibition of cell proliferation, whereas PGE2 treatment or COX-2 transfection reversed the inhibition by melatonin. Moreover, melatonin markedly inhibited phosphorylation of PI3K, Akt, PRAS40, and GSK-3 proteins, thereby inactivating the PI3K/Akt signaling pathway. Pretreatment with a PI3K- or an Akt-selective inhibitor or an Akt-specific siRNA blocked the melatonin-mediated inhibition of cell proliferation. Conversely, gene delivery of a constitutively active Akt effectively reversed the inhibition by melatonin. Furthermore, melatonin induced Apaf-1 expression, triggered cytochrome C release, and stimulated caspase-3 and caspase-9 activities and cleavage, leading to an activation of the Apaf-1-dependent apoptotic pathway. Pretreatment with an Apaf-1-specific siRNA effectively attenuated the melatonin-induced apoptosis. These results therefore indicate that melatonin inhibits cell proliferation and induces apoptosis in MDA-MB-361 breast cancer cells in vitro by simultaneously suppressing the COX-2/PGE2, p300/NF-κB, and PI3K/Akt/signaling and activating the Apaf-1/caspase-dependent apoptotic pathway.
Journal of Pineal Research 01/2012; 53(1):77-90. · 5.79 Impact Factor
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ABSTRACT: Nicotine, the major component in cigarette smoke, can promote tumor growth and angiogenesis, but the precise mechanisms involved remain largely unknown. Here, we investigated the mechanism of action of nicotine in human nasopharyngeal carcinoma (NPC) cells. Nicotine significantly promoted cell proliferation in a dose and time-dependent manner in human NPC cells. The mechanism studies showed that the observed stimulation of proliferation was accompanied by the nicotine-mediated simultaneous modulation of α7AChR, HIF-1α, ERK and VEGF/PEDF signaling. Treatment of NPC cells with nicotine markedly upregulated the expression of α7AChR and HIF-1α proteins. Transfection with a α7AChR or HIF-1α-specific siRNA or a α7AChR-selective inhibitor significantly attenuated the nicotine-mediated promotion of NPC cell proliferation. Nicotine also promoted the phosphorylation of ERK1/2 but not JNK and p38 proteins, thereby induced the activation of ERK/MAPK signaling pathway. Pretreatment with an ERK-selective inhibitor effectively reduced the nicotine-induced proliferation of NPC cells. Moreover, nicotine upregulated the expression of VEGF but suppressed the expression of PEDF at mRNA and protein levels, leading to a significant increase of the ratio of VEGF/PEDF in NPC cells. Pretreatment with a α7AChR or ERK-selective inhibitor or transfection with a HIF-1α-specific siRNA in NPC cells significantly inhibited the nicotine-induced HIF-1α expression and VEGF/PEDF ratio. These results therefore indicate that nicotine promotes proliferation of human NPC cells in vitro through simultaneous modulation of α7AChR, HIF-1α, ERK and VEGF/PEDF signaling and suggest that the related molecules such as HIF-1α might be the potential therapeutic targets for tobacco-associated diseases such as nasopharyngeal carcinomas.
PLoS ONE 01/2012; 7(8):e43898. · 4.09 Impact Factor
